Add TestGypXcodeNinja to run tests against the xcode-ninja generator

test/mac/gyptest-postbuild.py

Index: test/mac/gyptest-postbuild.py
diff --git a/test/mac/gyptest-postbuild.py b/test/mac/gyptest-postbuild.py
index 684e7b8426d1de9ed87e1e9fecf4db50c78f61b9..beaf09dab90959971ac4fa50282642e4a35f5f55 100755
--- a/test/mac/gyptest-postbuild.py
+++ b/test/mac/gyptest-postbuild.py
@@ -15,7 +15,9 @@ import sys
 if sys.platform == 'darwin':
   test = TestGyp.TestGyp(formats=['ninja', 'make', 'xcode'])
 
-  test.run_gyp('test.gyp', chdir='postbuilds')
+  test.run_gyp('test.gyp',
+               '-G', 'xcode_ninja_target_pattern=^.*$',
+               chdir='postbuilds')
 
   test.build('test.gyp', test.ALL, chdir='postbuilds')